#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
    int a = 0;
    int b = 0;
    int c = 0;
    while ((scanf("%d%d%d", &a, &b, &c) != EOF))
    {
        if (a + b > c && a - b < c)
        {
            if (a == b && b == c)
            {
                printf("Equilateral triangle!");
                printf("\n");
            }
            else if ((a == b && b != c) || (a == c && c != b) || (b == c && b != a))
            {
                printf("Isosceles triangle!");
                printf("\n");

            }
            else {
                printf("Ordinary triangle!");
                printf("\n");

            }
        }
        else
        {
            printf("Not a triangle!");
            printf("\n");

        }
    }
    return 0;
}
